1. Field of the Invention
Embodiments of the invention relate to the field of semiconductors, and more specifically, to low noise amplifiers.
2. Description of Related Art
The front end of a radio frequency (RF) receiver typically has a low noise amplifier (LNA), a mixer, and some filters. Since the LNA is the first stage of the receiver, its performance often sets the limits on the receiver performance. Usually, the LNA exhibits a 50Ω input impedance to the antenna so as to maximize the power delivery. Differential LNAs with inductors may be employed to provide such an input matching.
However, traditional differential LNAs may have some drawbacks. A typical differential LNA generally requires six single-ended inductors, thus occupying approximately twice the silicon area, and consumes more power compared to a single-ended LNA which uses three single-ended inductors. On the other hand, single-ended LNAs have worse common-mode rejection and even-order distortions than differential LNAs.